Study Finds Ethnicity Impacts Inflammatory Bowel Disease

A study led by Daniel A. Sussman, M.D., assistant professor of clinical medicine in the Division of Gastroenterology, and senior author Maria T. Abreu, M.D., professor of medicine and Chief of the Division of Gastroenterology, found that inflammatory bowel disease (IBD) presents differently in U.S.-born Hispanics than in foreign-born Hispanics and non-Hispanic white patients.

Published online in advance of print in The American Journal of Gastroenterology, the study, “Phenotypic Manifestations of Inflammatory Bowel Disease Differ Between Hispanics and Non-Hispanic Whites: Results of a Large Cohort Study,” evaluated 325 adult patients with IBD treated at University of Miami Hospital and Clinics and Jackson Memorial Hospital between 1998 and 2009. The cohort included 208 Hispanics, 68 percent of whom were foreign-born, and 117 non-Hispanic whites.

IBD is common—affecting almost 1 in 200 Americans. The two forms of IBD, Crohn’s disease and ulcerative colitis, are thought to be uncommon in Hispanics. These diseases cause inflammation and damage to the lining of the intestine, often requiring immunosuppressive therapy and surgery.

“Hispanic populations with inflammatory bowel disease are relatively under studied,” said Sussman. “The patient population served by the University of Miami Hospital and Jackson Memorial Hospital may be more representative of the U.S. Hispanic population than earlier studies of Hispanics.”

Sussman said that “differences exist in the manner by which inflammatory bowel diseases manifest among Hispanic patients.” “In contrast to previous studies, we were able to assess differences in disease manifestations between Hispanics who had migrated to the United States and U.S.-born Hispanics. Whereas non-Hispanic white patients tend to have more Crohn’s disease, we found that immigrants from Latin America had more ulcerative colitis and developed the disease much later in life. By one generation, American-born Hispanics more often had Crohn’s disease and developed the disease at about the same age as the non-Hispanic population. It is unclear what is responsible for this observation, but possibilities include changes in the environment with migration, diet, and other factors related to acculturation.”

The researchers also are looking at genetic differences in the different populations.

Disparities in prescriptions and the need for surgery were remarkable between ethnic groups. Non-Hispanic whites had a higher rate of surgeries related to IBD than Hispanics, and Hispanic participants were prescribed immunomodulators and biologics less often than non-Hispanic whites, though the prescription differences may be representative of issues related to insurance status rather than a difference in the biology of the disease.